Suppose over Sukkot, one's hotel for chol ha moed won't have a sukkah. I'd like to know what one can eat that won't trigger the "meals must be eaten in a sukkah" issues. (I'm knowledgeable enough about Judaism to know that the laws are often subject to debate).

2 Answers
2

1. A meal which requires the Brocho of Leishev BaSuccah to be eaten in the Succah:

Bread (made of the 5 grains) with the volume slightly larger than an egg (Shulchan Aruch OC 639,2 explained by Magen Avraham) even if eaten as a snack

Cake or biscuits that are made of the 5 Grains (wheat, barley, spelt, rye and oats) one would personally eat as a Meal (see Mishna Brura 16 quoting Maamar Mordechai ), this would include having Coffee with cake for Breakfast which is considdered nowadays a meal, likewise Kiddush on Shabbos morning with biscuits and cake.

2.A meal which should ideally be eaten in the Succah (Mishna Brura 15) but one does not make a Brocho Leishev Basuccah:

Fruit, meat fish and any foodstuff which is eaten as a fixed meal without bread

Bread which is only the volume of an egg or smaller

Cake even larger than the volume of an egg when its not a fixed meal

Wine eaten as a fixed meal

If one eats Fruit, meat, fish, wine or any non 5 grain foodstuffs as a snack throughout the day without sitting down to make a meal The Mishna Brura 15 says:
שלא בקביעות אין להחמיר כלל Without fixing a meal one does not have to be strict at all to eat in a Succah. So in your hotel during Chol Hamoed if you want you can constantly eat snacks of non 5 grain items though obviously if a Succah becomes available its an opportunity to fulfill a Mitzva of eating properly in a Succah which one shouldn't miss.

We eat and drink and sleep in the Sukkah all seven days, both day and
night, and we do not sleep outside of the Sukkah, even a very short
sleep. But one may eat an insubstantial meal outside of the Sukkah.
And how much is an insubstantial meal? Approximately an egg's worth of
a loaf of bread. And it is permitted to drink water and wine and eat
fruit even if he made it his meal (own opinion) outside of the Sukkah.
And he who is stringent upon himself, and will not drink even water
outside of the Sukkah, he is praised. And a dish made of the five
species [of grain], if he makes it his meal, it considered a proper
meal and requires a Sukkah.

According to the letter of the law one is only required to eat in the
Sukkah if he is eating more than a Kibeitza of bread or Mezonos
[within [the time limit of] Kdei Achilas Pras]. All foods which do not carry the blessing
of Mezonos or Hamotzi may be eaten outside the Sukkah without limit,
even if one sets a meal over those foods. However one who is stringent
to eat also these foods in the Sukkah, is praised.

There is some dispute whether non-hamotzi/mezonot products can be eaten outside a sukkah when they compose a full meal. For this reason, as well as to discuss whether it is appropriate to go to such a hotel, and whether one should travel to look for a sukkah, it is best to ask a rabbi who knows you (see also the end of here).